Steam-operated fire door



1929. R. H. SHEPARD 1,723,662

STEAM OPERATED FIREYDOOR Filed Oct. 1, 19.26 5 Sheets-Sheet l I v INVENTOR 9 ATTORNEY5' Aug. 6, 1929. R SHEPARD 1,723,662

STEAM OPERATED FIRE DOOR Filed Oct. 1, 1926 3 Sheets-Sheet 2 v I rm 7% ATTORNEYS R. H. SHEPARD- STEAM OPERATED FIRE DOOR Aug. 6, 1929.

s Sheets-Shet 5 Filed Oct. 1, 1926 INVENTOR wfiwm ATTORNEY$ Patented Aug. 6, 1929.

UNITED STATES 1,723,662 PATENT OFFICE.

RALPH H. SHEPARD, OF BRONXVILLE, NEW YORK, ASSIGNOR T0 FRANKLIN RAILWAY SUPPLY COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

STEAM-OPERATED FIRE DOOR.

Application filed October 1, 1926.

This invention relates to operating cylinders for fire box doors, such as are used on locomotives, and has for its primary objcc the provision of an operating cylinder and valve arrangement which is particularly adapted to utilize steam pressure, and which obviates certain difficulties and disadvantages heretofore encountered when operating such mechanisms with steam pressure. In operating 0 linders of this type heretofore used, diiiicufties were encountered in arranging the valve and cylinder inlet and exhaust ports so as to effectively discharge condensate, which accumulated in considerable quantities in the cylinder, and, at the same time, provide an arrangement of said ports which would provide for the cushioning of the movements of the doors.

0 overcome these difliculties, I have designed an apparatus which not only provides for an effective discharge of any condensate which may accumulate, but also materially reduces such condensate.

I have illustrated the invention in preferred form in the accompanying drawings,

wherein Fig. 1 is a front elevation of the door operating mechanism of my invention as applied to a locomotive furnace door of the butterfly t )e.

Fig. 2 is a side elevation of Fig. 1, with a portion of the back head of the boiler shown in cross section.

Fig. 3 is a section taken on the line 33 of Figure 4, of my improved operating cylinder and its associated controlling valve.

Fig. 4 is a plan view of the cylinder and valve arrangement, the piston being omitted, and

Figs. 5, 6 and 7 show various positions of the piston in the operating cylinder, as well as of the controlling valve therefor.

eferring now to Figs. 1 and 2, the fire box doors which are'of the gravity-closing type are indicated by the reference numeral 1 and are shown pivotally mounted for lateral swinging motion on a framework 2, which is secured to the back head of the boiler 3 around the opening into the fire box. The doors have meshing gear segments 5 which are cut with pivot pins 6 as centers. A hand operating lever 7 is secured to the right hand door 1 around its pivot pin 6 by a bolt 8, and serves to swing both the doors open by virtue of the meshing gear segments Serial No. 138,950.

An extension 64 is provided on the left hand gear segment; 5, to which the steam cylinder operating link 65 is secured by the pin connection (36. The other end of link 65 engages the pin 59 of the operating piston.

The steam operating cylinder 9 is mounted above the pivot pins 6 of the doors 1, and carries the controlling valve chamber 10. A valve operating lever 11, customarily actuated by the foot, is provided for opening the controlling valve in the chamber 10. This is accomplished through lever 12 pivoted at 13 on bracket 21, connecting link 14, lever 15 secured to the left hand door pivot pin (3 behind the cylinder 9, and arm 16, secured to the pin 6 in front of the doors, which is adapted to engage and raise the valve 17. The steam supply line 18 to the operating mechanism may be provided with atrap 19. and any suitable pressure regulator 20. steam exhaust line 22 may be provided to exhaust the steam from the operating mechanism outside of the locomotive cab.

Referring now to Figs. 3 and 4, the operating mechanism comprises a cylinder 23 and supporting bracket 24 cast integrally. Openings 25 and 26 are provided in the bracket 24 to receive the pivot pins 6. The controlling valve chamber 10 is secured to the cylinder by bolts 27. and has an annular shoulder 28 in the interior of the chamber on which the head 29 of the valve 17 is adapted to seat. A plug 30 closes the top of the valve chamber. and a spring 31 interposed between this plug and the valve head serves to assist in returning the valve to the closed position. passage 32 in the wall of the valve chamber 10 communicates. at one end, with the cavity 33, and. at the other end, with the passage 34, in the wall of the cylinder 23. which. in turn, communicates with the steam supply line 18. Two ports 35 and 36, one of which is restricted at 58, lead from the annular chamber 37 around the valve stem 38 to two corresponding passages 39 and. 40, in the wall of the cylinder 23. which, in turn. communicate with the annular chamber 41 through the ports 42 and 43. A port 44 opens from the passage 39 into the cylinder at a point just beyond the extreme left hand position of the piston. which is indicated, as a whole, by the reference numeral 45.

The piston 4-5 comprises a body proper 46; a member 47, having a projection 48 there- Ibo V raised position.

on threaded into the body 46, and having the annular channel 41 formed therearound; and a follower ring 49 screwed onto another projection 50 on the member 47 at the other end thereof. Packingring grooves 51 and packing rings 52 are provided between the member 47 and the body 46 on one side, and the follower 49 on the other side. The pin 59 extends through the opening in the cylinder wall, and is secured in the piston body 46 by aset screw 61. An oil cup 62 having a cap 63 is provided near the top of the cylinder. I

Exhaust ports 53 lead into the exhaust passage 54 in the wall of the valve chamber 10, which communicates, in turn, with the passages 55 and 56 in the cylinder wall and the exhaust pipe 22 discharging outside of the locomotive cab. The shoulder 57 of the valve 17 closes ports 53 when the valve is in The operation of the apparatus is as follows:

When it is desired to open the fire doors, the operating lever 11 is depressed, thereby raising the valve head129 from its seat 28, and closing the exhaust ports 53. Steam admitted into the chamber 33 through passages 34 and 32 now enters the chamber 37, and from there through ports 35 and 36 into the passages 39 and 40. Steam entering through restricted port 58 and passage 39 directly enters the cylinder-through the port 44, and the steam entering the port 36 and passage 40 enters the annular chamber 41 through port 43, and, from there, enters the passage 39 through the port 42 and also enters the cylinder through the port 44. Thus, the cylinder receives a large volume of steam to initiate the start of the piston stroke. The piston now advances to the position shown in Fig. 5, the head of the piston closing the ports 42 and 43, and thus cutting oii the major part of the steam supply. 'However, the momentum that the doors have received and the force exerted by the tendency of the steam which has already entered the cylinder to work .expansively are sufficient to carry the'head of the piston past the ports 42 and 43, thus reopening them and allowing the full volume of steam to enter the cylinder through ports 42, 43 and 44, to insure completion of the stroke (see Fig. 6). This is important in preventing sagging of the doors when they are in full open position, at which time the action of gravity tending to close them is greatest.

When it is desired to close the doors, the operating lever 11 is released, allowing the valve to reseat and open the exhaust ports 53. The weight of the open doors now returns the piston to the left hand position, forcing the steam in the cylinder out, at first, through the ports 42, 43 and 44, through the passages 39 and 40, ports 35 and 36, chamber 37, ports 53 and passages 55 and 56 to the exhaust pipe 22. When the piston returns just a little farther than the position shown in Fig. 7, the ports 42 and 43 are again closed and, substantially all of the exhaust area being cut off, the'steam remaining in the cylinder retards or cushions the movement of the piston and the doors. When the head of the piston passes the ports 42 and 43, a large exhaust area is again opened through port 44, passage 39, ports 42 and 43, to the chamber 37 and passage 55. This insures quick and free action of the doors just before closing.

The unrestricted exhaust at the start and finish of the return stroke of the piston materially reduces condensing of the steam, and the small clearance provided between the cylinder and piston heads, with the port 44 located therein, provide an effective discharge of any condensate whichmay accumulate, even to the end of the piston stroke.

1. A fire door operating mechanism comprising, in combination, a cylinder, piston, means for supplying operating fluid in comparatively large volume during initial move ment of the piston, means for subsequently reducing the supply of operating fluid during a portion of the piston stroke, and means for reestablishing a large volume supply during completion of the stroke.

2. A fire door operating mechanism comprising, in combination, a cylinder, a piston, means for supplyingoperating fluid in comparatively large volume during initial movement of the piston, means for subsequently reducing the supply of operating fluid during a portion of the piston stroke, and means for reestablishing a large volume supply during completion of the stroke, said several supply means serving as exhaust in reverse order upon return movement of the piston.

3. A fire door operating mechanism comprising, in combination, a cylinder, a piston, means for supplying operating fluid in comparatively large volume during initial movement of thepiston, and during completion of the piston stroke, and means'on said piston for blocking off a part of said supplying means during the intermediate portion of the piston stroke.

4. A door operating motor comprising, in combination, a cylinder, a piston, a steam inlet port, a restricted inlet port, a valve for controlling the supply of steam to said ports, and means on the piston for closing said first inlet port during intermediate movement of the piston but adapted to reopen it during final movement thereof, said ports acting as exhaust ports in reverse order during return movement of the piston.

5. A door operating motor comprising, in combination, a cylinder, a piston, a steam inlet passage in the cylinder wall, a port between said passage and an end of the cylinder, a second port between said passage and a point intermediate the cylinder ends, a second steam passage with port also opening into the cylinder intermediate its ends, a cavity in the piston for connecting said intermediate ports during initial movement of the piston whereby the full capacity of both passages is delivered to said first port, and means on the piston for closing said intermediate ports during intermediate movement thereof, said means adapted to again uncover said intermediate ports during final piston movement.

6. A door operating motor comprising, in combination, a cylinder, a piston, a steam inlet passage in the cylinder wall, a port between said passage and an end of the cylinder, a second port between said passage and a point intermediate the cylinder ends, a second steam passage with port also opening into the cylinder intermediate its ends, a cavity in the piston for connecting said intermediate ports during initial movement of the piston whereby the full capacity of both passages is delivered to said first port, and means on the piston for closing said intermediate ports during intermediate movement thereof, said means adapted to again uncover said intermediate ports during final piston movement, and said several supply passages and ports being adapted to serve as exhaust means in reverse order during return movement of the piston.

7. A door operating motor comprising, in combination, a cylinder, a piston, a steam inlet passage in the cylinder wall having a restriction therein at its inlet end, a port between said passage and an end of the cylinder, a second port between said passage and a point intermediate the cylinder ends, a second steam passage with port also opening into the cylinder intermediate its ends, a cavity in the piston for connecting said intermediate ports during initial movement of the piston whereby the full capacity of both passages is delivered to said first port, and means on the piston for closing said intermediate ports during intermediate movement thereof, said means adapted to again uncover said intermediate ports during final piston movement, and said restriction allowing a quantity of steam to pass into said first passage which, together with the expansive properties of the steam admitted during initial movement, is sufficient to carry the piston through the intermediate portion of its stroke.

8. A door operating motor comprising, in combination, a cylinder, a piston, a steam inlet passage in the cylinder wall having a restriction therein at its inlet end, a port between said passage and an end of the cylinder, a second port between said passage and a. point intermediate the cylinder ends, a second steam passage with port also open ing into the cylinder intermediate its ends, a cavity in the piston for connecting said intermediate ports during initial movement of the piston whereby the full capacity of. both passages is delivered to said first port, and means on the piston for closing said intermediate ports during intermediate movement thereof, said means adapted to again uncover said intermediate ports during final. piston movement, and said restriction allowing a quantity of steam to pass into said first passage which, together with the expansive properties of the steam admitted during initial movement, is sufficient to carry the piston through the intermediate portion of its stroke, and said restriction serving to cushion the return movement of the piston during the intermediate portion of its stroke.

9. A door operating motor comprising, in combination, a cylinder, a piston, a steam inlet port, a restricted inlet port, a valve for controlling the supply of steam to said ports, and means on the piston for closing said first inlet port during intermediate movement of the piston but adapted to reopen it during final. movement thereof, said restricted port having an area which, together with the expansion of the steam admitted to the cylinder during initial movement of the piston, is suflicient to carry the piston through the intermediate portion of its stroke, and said. ports acting as exhaust ports in reverse order during return movement of the piston.

In testimony whereof I have hereunto signed my name.

RALPH H. SHEPARD. 

